A bellows fatigue testing device and method

Abstract

The application discloses a corrugated pipe fatigue degree testing device and testing method, which comprises a testing mechanism for detecting the corrugated pipe fatigue degree, a control unit electrically connected with the testing mechanism for receiving control instructions output by the control unit, wherein the testing mechanism comprises a mounting rack for mounting components and the corrugated pipe, a testing rack arranged on the mounting rack for mounting and testing the corrugated pipe, a position detection unit arranged on the mounting rack and the testing rack for real-time detection of the mounting position of the corrugated pipe, and an air pressure detection unit arranged on the mounting rack for real-time detection of the air tightness inside the corrugated pipe. The three detection units of the limit, air pressure and length are in progressive interlocking control with the control unit, so that many testing defects caused by the lack of linkage correction in the traditional three types of detection are solved, the testing procedures are checked step by step, and the standard is achieved progressively, and the problems of the traditional testing servo displacement amplitude drift and unstable vacuum pressure difference are avoided.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and specifically to a bellows fatigue testing device and testing method. Background Technology

[0002] Precision bellows for semiconductor vacuum systems are used in vacuum valves and wafer transport mechanisms. During operation, they are affected by assembly deviations and the reciprocating motion of the equipment, and continuously subjected to alternating lateral displacements perpendicular to their own axis. At the same time, they are in an ultra-high vacuum pressure difference environment for a long time. The lateral fatigue testing device is used to simulate this actual working condition. Its working principle is as follows: the two ends of the bellows are rigidly sealed and clamped, and the inner cavity maintains the vacuum pressure difference corresponding to the semiconductor equipment. The loading mechanism drives one end of the bellows to make uniform reciprocating left and right offset movements along the vertical axis. A fixed displacement amplitude and cycle frequency are set, and cyclic loading tests are continuously carried out. The test system is equipped with a helium mass spectrometry leak detection module to monitor the sealing performance of the bellows in real time throughout the process. The number of complete cycles is recorded by a counting mechanism until the specimen leaks and fatigue failure is determined. The entire device relies on servo drive to achieve high-precision lateral displacement control, which can stably reproduce the lateral alternating stress state of the semiconductor bellows and intuitively obtain the fatigue service life of the bellows under the combined action of lateral displacement and vacuum pressure difference, thereby evaluating the long-term reliability of the product in semiconductor vacuum equipment. The existing semiconductor bellows lateral fatigue testing device simulates real-world operating conditions by servo lateral reciprocating loading, maintaining ultra-high vacuum in the inner cavity, and real-time leak detection using helium. However, it lacks pre-testing of positioning, length, and pre-installed airtightness. After clamping, three types of errors—dimensional deviation, coaxial eccentricity, and micro-leakage—are coupled and superimposed, introducing additional axial tension and compression, and eccentric torsion stress, which violates the standard stress conditions of the test. Without linkage correction for the three types of testing, servo displacement amplitude drift, unstable vacuum pressure difference, inability to distinguish between tooling leaks and bellows body leaks, specimens are prone to premature plastic failure, fatigue cycle count determination is distorted, test signals in the same batch are discrete, the actual stress state of the bellows cannot be accurately reproduced, and it is difficult to objectively evaluate the long-term fatigue reliability under vacuum conditions.

[0003] Therefore, providing a bellows fatigue testing device that avoids premature plastic failure of specimens, distortion in the determination of fatigue cycle count, discrete test data in the same batch, and inability to accurately reproduce the actual stress state of the bellows has become an urgent problem to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of plastic failure, distorted determination of fatigue cycle count, discrete test data in the same batch, and inability to accurately reproduce the actual stress state of the bellows in the existing bellows fatigue testing device.

[0005] To address the aforementioned problems, this invention discloses a bellows fatigue testing device, comprising: a testing mechanism for detecting the fatigue of the bellows; and a control unit electrically connected to the testing mechanism for receiving control commands output by the control unit. The testing mechanism includes: a mounting frame for mounting the component and the bellows; a testing frame disposed on the mounting frame for mounting and testing the bellows; a position detection unit disposed on the mounting frame and the testing frame for real-time detection of the bellows' installation position; an air pressure detection unit disposed on the mounting frame for real-time detection of the bellows' internal airtightness; a length detection unit disposed at the bottom of the mounting frame for detecting the length of the bellows; and a dynamic movement unit disposed at the bottom of the mounting frame for driving the testing frame to reciprocate. The corrugated pipe is disposed between the test frame and the mounting frame. The position detection unit, the air pressure detection unit, and the length detection unit are all connected to the control unit. After the position detection unit, the air pressure detection unit, and the length detection unit all detect that they are normal, the dynamic movement unit drives the test frame to reciprocate under the control of the control unit. During the movement, the test frame will compress or stretch the corrugated pipe.

[0006] By adopting the above technical solution, the limit, air pressure, and length detection units and the control unit form a progressive interlocking control, effectively solving many testing defects caused by the lack of linkage correction in traditional three-type detection. This device realizes step-by-step verification and progressive compliance of the testing process, avoiding the problems of servo displacement amplitude drift and unstable vacuum pressure difference in traditional testing. It can accurately distinguish between tooling leakage and bellows body leakage, avoiding misjudgment of faults. At the same time, through triple accurate verification of pre-alignment, airtightness, and deformation size, fatigue testing is prevented from starting under substandard working conditions of the bellows, effectively preventing premature plastic failure of the specimen. It solves the problems of distorted fatigue cycle determination and large dispersion of test signals in the same batch. Relying on real-time signal feedback from each detection unit, the dynamic moving unit can synchronously and adaptively adjust its motion state to accurately simulate the real stress conditions of the bellows, ensuring that the testing process is stable and controllable. This invention greatly improves the accuracy and repeatability of bellows fatigue testing, and can objectively and accurately evaluate the long-term fatigue reliability of bellows under vacuum conditions, effectively improving the uniformity and accuracy of batch test data.

[0007] According to another specific embodiment of the present invention, the position detection unit, the air pressure detection unit, and the length detection unit are pre-set with their respective reference parameters by the control unit, and are used to collect the corrugated pipe installation detection data and compare and verify it with the reference parameters.

[0008] According to another specific embodiment of the present invention, the position detection unit is disposed on the axial outer wall of the mounting frame and the test frame, and is used to detect the center distance between the corrugated pipe and the mounting frame and the test frame.

[0009] According to another specific embodiment of the present invention, the air pressure detection unit is disposed on the axial side of the bellows and mounting bracket near the length detection unit, and is used to detect the air tightness of the bellows under pressurized conditions in real time.

[0010] According to another specific embodiment of the present invention, a length detection unit is provided along the bottom of the corrugated pipe on the side away from the test frame axial direction, which is used to cooperate with the dynamic moving unit to drive the test frame and the corrugated pipe to reciprocate sampling and expansion, and to detect the axial deformation dimension of the corrugated pipe.

[0011] According to another specific embodiment of the present invention, the length detection unit includes a mounting block and a laser displacement sensor. The mounting block is fixedly installed at the end of the slide rail A away from the dynamic moving unit, and the laser displacement sensor is fixedly installed on the side of the mounting block close to the dynamic moving unit for detecting the axial extension and contraction of the corrugated pipe driven by the test frame.

[0012] According to another specific embodiment of the present invention, one side of the dynamic moving unit and the bottom of the test frame are connected to each other, so that the dynamic moving unit drives the test frame to reciprocate, and performs installation inspection and fatigue test on the corrugated pipe.

[0013] According to another specific embodiment of the present invention, the dynamic movement unit receives real-time electrical signals fed back by the position detection unit and the air pressure detection unit through the control unit, and the dynamic movement unit adjusts its own movement distance and movement speed in real time based on the signal values.

[0014] According to another specific embodiment of the present invention, the control unit outputs a counting detection command to the length detection unit for the working period corresponding to the bellows test, so as to switch the length detection unit to the counting detection working state.

[0015] This invention also discloses a method for testing the fatigue of bellows, the method comprising the following steps: S1. Preparation steps: Place the bellows to be tested inside the testing mechanism, connect the electrical connection between the testing mechanism and the control unit, and pre-set the reference parameters of the position detection unit, air pressure detection unit and length detection unit through the control unit; S2. Limit detection step: Then, based on the preset parameters of the position detection unit, adjust the relative position of the bellows and the test mechanism to ensure that the center distance between the two matches the preset alignment standard. If the limit detection fails to meet the standard, the control unit shall prohibit the inflation of air into the bellows. S3. Air pressure test procedure: After alignment, the control unit injects gas into the bellows. After the air pressure reaches the preset parameter, the inflation stops and a pressure holding test is performed. If the air pressure value does not fall below the reference parameter during the pressure holding process, the air tightness is deemed to be qualified. If the air tightness test fails, the control unit prohibits the start of the length test. S4. Length detection step: At this time, the control unit issues a drive command to control the dynamic moving unit to drive the bellows to complete the reciprocating extension and retraction sampling, and cooperates with the length detection unit to verify the axial deformation dimension of the bellows. When the axial deformation dimension does not meet the standard, the control unit locks the dynamic moving unit and prohibits the start of the formal fatigue extrusion tensile test. S5. Inspection and qualification steps: After the limit, air pressure and length tests are all up to standard, the control unit finally controls the dynamic moving unit to drive the bellows to perform fatigue test. S6. Bellows fatigue test motion steps: During the reciprocating motion of the bellows driven by the dynamic moving unit, the control unit continuously collects the feedback signals from the air pressure detection unit and the position detection unit in real time. S7. Bellows fatigue test motion acceleration steps: If the air pressure and limit reference values ​​do not change after a preset number of cycles, the dynamic moving unit will gradually accelerate according to the preset gradient. During acceleration, the bellows will move left and right to complete the fatigue test. S8. Corrugated pipe fatigue test motion deceleration steps: When the air pressure and limit reference parameters deviate, the control unit will control the whole machine to stop working, and at the same time, the dynamic moving unit set inside the whole machine will stop driving the corrugated pipe to run. Attached Figure Description

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments: Figure 1 This is a three-dimensional structural schematic diagram of a bellows fatigue testing device and testing method provided by the present invention; Figure 2 This is a schematic diagram of the internal overall structure of a bellows fatigue testing device and testing method provided by the present invention; Figure 3 This is a two-dimensional front view of the internal structure of the bellows fatigue testing device and testing method provided by the present invention. Figure 4 This is a schematic diagram of a two-dimensional series structure of a proportional flow control valve and a speed regulating valve in a bellows fatigue testing device and method provided by the present invention. Figure 5 This is a two-dimensional structural diagram of an eight-corrugated corrugated pipe under compression, which is a corrugated pipe fatigue testing device and testing method provided by the present invention. Figure 6This is a two-dimensional structural diagram of a nine-wave corrugated pipe under compression, which is a corrugated pipe fatigue testing device and testing method provided by the present invention.

[0017] Figure label: 1. Testing mechanism; 22. Flange connector A; 24. Flange connector B; 21. Slide rail A; 26. Slide rail B; 25. Slider; 27. Moving flange; 31. Displacement sensor bracket; 32. Displacement sensor; 41. Injection nozzle; 42. Pressure sensor; 51. Mounting block; 52. Laser displacement sensor; 61. Cylinder; 62. Speed ​​control valve; 63. Proportional flow control valve; 64. Telescopic rod. Detailed Implementation

[0018] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a deep understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0019] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used in the placement of the product of the invention. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0020] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0021] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "provided with," "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0022] like Figures 1 to 4 As shown, this invention discloses a bellows fatigue testing device, comprising a testing mechanism 1 for detecting the fatigue of the bellows; and a control unit electrically connected to the testing mechanism 1 for receiving control commands output by the control unit. The testing mechanism 1 includes: a mounting frame comprising flange connectors A22 and B24 for mounting components and the bellows; a testing frame comprising a movable flange 27 mounted on the mounting frame for installing and testing the bellows; a position detection unit mounted on the mounting frame and the testing frame for real-time detection of the bellows installation position; an air pressure detection unit mounted on the mounting frame for real-time detection of the internal airtightness of the bellows; a length detection unit located at the bottom of the mounting frame for detecting the length of the bellows; and a dynamic movement unit located at the bottom of the mounting frame for driving the testing frame to reciprocate. The corrugated pipe is located between the test frame and the mounting frame. The position detection unit, air pressure detection unit, and length detection unit are all connected to the control unit. After the position detection unit, air pressure detection unit, and length detection unit all detect that they are normal, the dynamic movement unit drives the test frame to reciprocate under the control of the control unit. During the movement, the test frame will compress or stretch the corrugated pipe.

[0023] In other words, the testing mechanism 1 has two symmetrical bellows inside. The testing mechanism 1 is electrically connected to the control unit, which can issue commands to the testing mechanism 1 and receive feedback signals from all units inside the testing mechanism 1. A position detection unit is provided at the connection between the two bellows and the testing mechanism 1. When assembling the bellows, the center distance between the two bellows can be calibrated through the position detection unit. A pressure detection unit is provided along one side of the bellows' X-axis. The bellows can be pre-filled with suitable gas and pressurized to test the airtightness of the assembled bellows. After the airtightness test is qualified, the length detection unit, in conjunction with the dynamic movement unit, drives the bellows to perform left and right extension and retraction sampling actions to collect the size signals of the two bellows. Only when all three types of benchmark parameters meet the standards will the dynamic movement unit drive the bellows connected at the top to carry out fatigue testing.

[0024] For details, see Figures 1 to 2As shown, in this embodiment, symmetrically arranged flange connectors A22 and B24 are fixedly installed inside the testing mechanism 1. Flange connector A22 is connected to flange connector B24 and one end flange of two bellows. A slide rail A21 is provided at the bottom of flange connectors B24 and A22, through which the dynamic moving unit can be mounted on the surface. Two slide rails B26 are mirrored at both ends of slide rail A21. A slider 25 is slidably fitted on the top of slide rail B26. A movable flange 27 is fixedly installed on the top of one side of the dynamic moving unit. The two ends of the movable flange 27 are fixedly connected by the flange and two bellows at the ends away from the flange connector A22 and flange connector B24. Several position detection units are arranged in an axial array on the flange connector A22, flange connector B24, and movable flange 27. The top of the slider 25 is fixedly connected to the bottom of both ends of the movable flange 27. It should also be noted that a length detection unit is fixedly installed on the top of the slide rail A21 at the end away from the dynamic moving unit, and a pressure detection unit is fixedly installed on the side of the flange connector A22 and flange connector B24 away from the bellows. The control unit presets the rated reference parameters for the air pressure detection unit, position detection unit, and length detection unit; one end of each of the two bellows is assembled to the flange connector A22 and flange connector B24 respectively via flanges, and the other end is connected to the movable flange 27 via flanges. After assembly, the control unit sets the limit adjustment threshold and starts the calibration program. During the adjustment process, the position detection unit sends a position signal back to the control unit in real time. Only when the feedback signal is completely matched with the preset parameters can the alignment calibration be considered complete. In this equipment, the position detection unit, air pressure detection unit, and length detection unit are all electrically connected to the control unit. The three units rely on the control unit to construct a hierarchical interlocking control logic. Each detection process has strict sequential execution permission restrictions. The system will first start the limit detection. If the limit detection signal exceeds the preset tolerance or the alignment is unqualified, the position detection unit sends an abnormal signal to the control unit. The control unit immediately executes the interlocking lock and directly closes the start permission of the air pressure detection unit, making it impossible to carry out subsequent inflation and airtightness testing. Only when the limit detection feedback a qualified signal will the control unit unlock the air pressure detection channel. After calibration, the control unit inflates the inner cavities of the two bellows through the injection nozzle 41 on the flange connector A22. The air pressure detection unit monitors the internal pressure in real time. When the air pressure reaches the preset standard, it sends feedback to the control unit, and the equipment immediately stops inflating and enters the pressure holding stage. The pressure holding time is controlled between 10 seconds and 1 minute. If the air pressure does not change after the pressure holding is completed, the air tightness is deemed to be qualified. If the air pressure is lower than the reference parameter during the pressure holding stage and the air tightness test is unqualified, the air pressure detection unit sends a fault signal, the control unit triggers the interlock protection, blocks the start command of the length detection unit, and stops the sampling of the bellows expansion and contraction dimensions. Only after both the limit and airtightness tests pass sequentially will the control unit grant the length detection unit operating permission and issue a command to the dynamic moving unit, causing the top-fixed moving flange 27 to perform left-right reciprocating extension and retraction sampling. The length detection unit collects the bidirectional displacement of the moving flange 27 and compares the displacement values ​​on both sides to determine whether the dimensions of the two symmetrical bellows match. If the dimension detection result deviates from the reference parameter, the control unit will maintain interlocking and lock the dynamic moving unit, prohibiting it from conducting fatigue compression and tensile tests. Only when all three parameters—limit, airtightness, and dimensions—meet the standards will the control unit output a formal test command, driving the moving flange 27 to reciprocate left and right, continuously compressing and stretching the bellows, and initiating the fatigue test. The entire system relies on a progressive interlocking mechanism with three-level detection units providing sequential feedback and control units implementing hierarchical authority management. If any preceding detection fails, the initiation path for all subsequent detection and testing procedures will be cut off. This structure can prevent unqualified test pieces with misalignment, sealing leakage, or out-of-tolerance dimensions from directly entering fatigue testing, prevent bellows damage and pressure loss under pressurized conditions, and save on the air and electricity consumed by ineffective testing, thus balancing the operational safety and testing efficiency of the entire testing process.

[0025] The above technical solution, employing a symmetrical double-bellows testing structure, coupled with a progressive interlocking control system comprised of limit, air pressure, and length three-level detection units and a PLC control unit, completely solves the industry pain points of traditional bellows fatigue testing, such as lack of linkage correction, poor detection accuracy, data distortion, and inaccurate fault diagnosis. This device precisely calibrates the center distance of the double-bellows assembly through a position detection unit, eliminating testing errors caused by assembly misalignment. Relying on the air pressure detection unit's 10-second to 1-minute pressure holding detection mode, combined with a 100kPa reference pressure graded monitoring logic, it can accurately distinguish between tooling leaks and bellows body leaks. Simultaneously, it adaptively adjusts speed and stops based on the air pressure attenuation, effectively preventing sudden bellows rupture and pressure release during pressurized testing, ensuring testing safety. The length detection unit verifies the consistency of axial expansion and contraction displacement of the double bellows, which can quickly identify dimensional deviations of bellows with different wave numbers and specifications, and prevent test failures caused by uneven extrusion stroke on both sides. At the same time, the device relies on strict step-by-step interlocking logic. If the previous test fails, all subsequent processes are locked, preventing unqualified specimens from entering the fatigue test from the source. With integrated counting function and PLC intelligent adaptive control, the fatigue cycle count can be accurately counted. It can also autonomously adapt to the detection threshold of different bellows specifications without repeated manual adjustments, effectively reducing test energy consumption and air source loss. It greatly improves the uniformity, accuracy and repeatability of synchronous fatigue testing of double bellows, can truly reproduce the actual stress state of the bellows, and objectively evaluate the long-term fatigue reliability of the bellows under vacuum conditions.

[0026] For details, see Figure 1As shown, the position detection unit is located at the connection between the bellows and the test mechanism 1, and is used to detect the center distance between the bellows and the test mechanism 1. The position detection unit includes a displacement sensor bracket 31 and a displacement sensor 32. The displacement sensor bracket 31 is fixedly assembled on the outer peripheral wall of the flange connector A22, the flange connector B24, and the movable flange 27, and the displacement sensor 32 is fixedly connected to the outer wall of the displacement sensor bracket 31.

[0027] Combined with appendix Figure 1 The bottom of the displacement sensor 32 is directly opposite the connection position of the two bellows. When assembling the bellows, the displacement sensor 32 can transmit the assembly displacement signal to the control unit to complete the calibration of the center distance between the bellows and the flange connector A22, flange connector B24, and moving flange 27.

[0028] like Figure 1 The air pressure detection unit is set on one side of the bellows and the test mechanism 1 along the X-axis. It is used to detect the air tightness of the bellows under pressurized conditions. The air pressure detection unit includes an injection nozzle 41 and a pressure sensor 42. The injection nozzle 41 is fixedly connected to the side of the flange connector A22 away from the bellows. The pressure sensor 42 is fixedly connected to the outer wall of the side of the flange connector B24 away from the flange connector A22. like Figure 1 The control unit shown injects air into the interior of two bellows set along the X-axis through the injection nozzle 41. The gas pressure is detected by the gas pressure detection unit. When the gas reaches the reference parameter, the gas injection will stop. The injection nozzle 41 is a one-way valve structure, which allows the bellows to undergo a pressure holding test, thereby ensuring the airtightness before the test.

[0029] like Figure 1 The length detection unit is arranged along the axial direction of the bellows, which is used to cooperate with the dynamic moving unit to drive the bellows to reciprocate sampling and expansion and contraction, and to detect the axial deformation size of the bellows. The length detection unit includes a mounting block 51 and a laser displacement sensor 52. The mounting block 51 is fixedly installed at the end of the slide rail A21 away from the dynamic moving unit, and the laser displacement sensor 52 is fixedly installed on the side of the mounting block 51 close to the dynamic moving unit. When it is necessary to check the dimensional consistency of two sets of symmetrically arranged bellows, the control unit drives the dynamic moving unit to move the moving flange 27 left and right and compress the bellows on both sides. During the compression operation, the laser displacement sensor 52 detects the displacement of the moving flange 27 to the left and right in real time and compares whether the travel on both sides is equal. If the specifications of the two bellows are different, for example, one side is an eight-wave bellows and the other side is a nine-wave bellows, the difference in the number of waves will lead to an inconsistency in the allowable axial compression: the moving flange 27 has a shorter travel distance towards the nine-wave bellows side and a longer travel distance towards the eight-wave bellows side. Figure 3The X-axis direction is shown in Figure 5. The shaded area on the left corresponds to the extrusion stroke of the eight-corrugated pipe, and the shaded area on the right corresponds to the extrusion stroke of the nine-corrugated pipe. It can be seen from the comparison that the extrusion stroke of the eight-corrugated pipe is significantly greater than that of the nine-corrugated pipe. The mounting block 51 collects the displacement difference signal on both sides and feeds it back to determine that the two corrugated pipes are mismatched in size. The purpose of this displacement detection is to avoid the problem of test data distortion caused by the inconsistent extrusion stroke of the two corrugated pipes under fatigue test conditions.

[0030] like Figure 3 As shown, the dynamic moving unit is set on the bellows testing station and is used to test the fatigue of the bellows. The moving unit also includes a cylinder 61, a speed regulating valve 62, a proportional flow control valve 63, and a telescopic rod 64. The cylinder 61 is fixedly installed on the upper part of the slide rail A21 away from the mounting block 51. The speed regulating valve 62 is fixedly connected to the side of the cylinder 61. The proportional flow control valve 63 is fixedly connected to the end of the speed regulating valve 62 away from the cylinder 61. The telescopic rod 64 is movably sleeved inside the cylinder 61. The top of the telescopic rod 64 is fixedly connected to the bottom of the moving flange 27. During equipment operation, the proportional flow control valve 63 is connected to an external air source. The external air source delivers a medium into the cylinder 61, which drives the internally mounted telescopic rod 64 to reciprocate. During this reciprocating motion, combined with the attached... Figure 3 It is known that the aforementioned movable flange 27 can move left and right along the X-axis to perform compression and tension actions on the bellows connected to it, thereby completing the bellows fatigue test. At the same time, the proportional flow control valve 63 is electrically connected to the pressure sensor 42 and the displacement sensor 32 via the control unit. During the compression and tension test of the bellows, the control unit continuously collects the detection signals transmitted by the pressure sensor 42 and the displacement sensor 32. When the two signals collected do not change, the control unit regulates the proportional flow control valve 63 to adjust the exhaust volume and suction volume inside the cylinder 61, thereby causing the telescopic rod 64 to drive the movable flange 27 to gradually increase the reciprocating speed, continuously performing compression and tension fatigue tests on the bellows connected at both ends. When the control unit collects the values ​​fed back by the pressure sensor 42 and the displacement sensor 32, which deviate from the rated reference parameters, the test mechanism 1 will immediately stop all operations and directly terminate the current bellows fatigue test. It should also be noted that: the pressure sensor 42 detects a reference pressure of 100 kPa. When the bellows leaks and the internal air pressure drops to 90 kPa, the test mechanism 1 stops operating. When the internal air pressure gradually decreases from 100 kPa to 95 kPa, the control unit sends an adjustment command to the proportional flow control valve 63. The proportional flow control valve 63 controls the cylinder 61 to reduce its speed to decrease the reciprocating motion speed. As the air pressure continues to gradually decrease from 95 kPa to 90 kPa, the cylinder 61 drives the telescopic rod 64 to slowly return to its original position and complete the shutdown action. If the air pressure drops suddenly and falls directly from 100 kPa to 90 kPa, the test mechanism 1 immediately stops and terminates the test, without any initial speed reduction buffer process. Similarly, the displacement sensor 32 monitors the center distance of the bellows assembly in real time. If the detected value deviates slightly and slowly from the reference tolerance range, the control unit simultaneously sends a speed reduction command to the proportional flow control valve 63 to reduce the reciprocating speed of the cylinder 61. If the displacement deviation continues to increase and reaches the shutdown threshold, the cylinder 61 drives the telescopic rod 64 to slowly return to its original position to complete the shutdown. If the displacement value changes drastically in an instant and a sudden assembly misalignment occurs, the testing mechanism 1 immediately stops and terminates the test.

[0031] The control unit outputs a counting detection command to the length detection unit for the working period corresponding to the bellows test, which drives the length detection unit to switch to the counting detection working state. This counting function is implemented by the laser displacement sensor 52. The laser displacement sensor 52 first completes the length consistency detection process of the two bellows. During the subsequent fatigue test, it can collect the number of reciprocating movements generated by the moving flange 27 extruding the bellows driven by the dynamic moving unit in real time, and simultaneously transmit the collected counting data to the control unit in real time, so as to accurately record and count the total number of fatigue extrusion cycles of the bellows. It should also be noted that the above-mentioned control unit is a PLC, which serves as the industrial control core of the entire device. It can collect feedback signals from various detection elements, perform data calculations and logical judgments, and output control signals to drive pneumatic actuators. At the same time, the PLC has data storage and intelligent learning functions. It can continuously collect the stroke and cycle count data returned by the laser displacement sensor 52, and autonomously establish a standard judgment model by combining multiple sets of detection samples such as airtight pressure changes and displacement deviations. It can automatically adapt to the detection thresholds of bellows with different wave numbers and specifications, without the need for repeated manual parameter adjustments, and achieve adaptive control of the detection and fatigue test process. like Figure 4 As shown, the proportional flow control valve 63 and the speed control valve 62 are connected in series. When the proportional flow control valve 63 fails, it can be manually adjusted through the speed control valve 62 to control the speed of the cylinder 61 driving the telescopic rod 64.

[0032] It should also be noted that rigid limit sensors are installed at both ends of slide rail A21. The control cylinder 61 drives the telescopic rod 64 to slide back and forth along slide rail A21. When the telescopic rod 64 moves to the end of the slide rail, it touches and triggers the corresponding rigid limit sensor. During normal operation, the sensor sends the arrival signal to the controller, which drives the solenoid valve to switch, thereby realizing the continuous reciprocating action of the control cylinder 61. If the proportional flow control valve 63 is stuck or the program is abnormal, causing the telescopic rod 64 to move beyond its travel, the rigid limit sensor can cut off the power output in hardware to prevent the telescopic rod 64 from rushing out of slide rail A21. It also has the dual functions of reciprocating stroke reversal detection and overtravel safety protection.

[0033] This invention also discloses a method for testing the fatigue of bellows, comprising the following steps: S1. Preparation steps: Place the bellows to be tested inside the testing mechanism, connect the electrical connection between the testing mechanism and the control unit, and pre-set the reference parameters of the position detection unit, air pressure detection unit and length detection unit through the control unit; S2. Limit detection step: Then, based on the preset parameters of the position detection unit, adjust the relative position of the bellows and the test mechanism to ensure that the center distance between the two matches the preset alignment standard. If the limit detection fails to meet the standard, the control unit shall prohibit the inflation of air into the bellows. S3. Air pressure test procedure: After alignment, the control unit injects gas into the bellows. After the air pressure reaches the preset parameter, the inflation stops and a pressure holding test is performed. If the air pressure value does not fall below the reference parameter during the pressure holding process, the air tightness is deemed to be qualified. If the air tightness test fails, the control unit prohibits the start of the length test. S4. Length detection step: At this time, the control unit issues a drive command to control the dynamic moving unit to drive the bellows to complete the reciprocating extension and retraction sampling, and cooperates with the length detection unit to verify the axial deformation dimension of the bellows. When the axial deformation dimension does not meet the standard, the control unit locks the dynamic moving unit and prohibits the start of the formal fatigue extrusion tensile test. S5. Inspection and qualification steps: After the limit, air pressure and length tests are all up to standard, the control unit finally controls the dynamic moving unit to drive the bellows to perform fatigue test. S6. Bellows fatigue test motion steps: During the reciprocating motion of the bellows driven by the dynamic moving unit, the control unit continuously collects the feedback signals from the air pressure detection unit and the position detection unit in real time. S7. Bellows fatigue test motion acceleration steps: If the air pressure and limit reference values ​​do not change after a preset number of cycles, the dynamic moving unit will gradually accelerate according to the preset gradient. During acceleration, the bellows will move left and right to complete the fatigue test. S8. Corrugated pipe fatigue test motion deceleration steps: When the air pressure and limit reference parameters deviate, the control unit will control the whole machine to stop working, and at the same time, the dynamic moving unit set inside the whole machine will stop driving the corrugated pipe to run.

[0034] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A bellows fatigue testing device, characterized in that, include: Testing facilities are used to detect the fatigue level of bellows; A control unit, electrically connected to the testing mechanism, is used for the testing mechanism to receive control commands output by the control unit, wherein the testing mechanism includes: Mounting brackets are used for mounting components and bellows; A test fixture, mounted on the mounting frame, is used for the installation and testing of the bellows; A position detection unit is provided on the mounting frame and the test frame, and is used to detect the installation position of the corrugated pipe in real time; A pressure detection unit, mounted on the mounting bracket, is used to detect the airtightness inside the bellows in real time. A length detection unit is located at the bottom of the mounting bracket and is used to detect the length of the corrugated pipe; A dynamic moving unit is located at the bottom of the mounting frame and is used to drive the test frame to reciprocate. The corrugated pipe is disposed between the test frame and the mounting frame. The position detection unit, the air pressure detection unit, and the length detection unit are all connected to the control unit. After the position detection unit, the air pressure detection unit, and the length detection unit all detect that they are normal, the dynamic movement unit drives the test frame to reciprocate under the control of the control unit. During the movement, the test frame will compress or stretch the corrugated pipe.

2. The bellows fatigue testing device according to claim 1, characterized in that, The position detection unit, air pressure detection unit, and length detection unit are pre-set with their respective reference parameters through the control unit, which are used to collect corrugated pipe installation detection data and compare and verify it with the reference parameters.

3. The bellows fatigue testing device according to claim 2, characterized in that, The position detection unit is disposed on the axial outer wall of the mounting frame and the test frame, and is used to detect the center distance between the corrugated pipe and the mounting frame and the test frame.

4. The bellows fatigue testing device according to claim 3, characterized in that, The air pressure detection unit is located on the axial side of the bellows and mounting bracket near the length detection unit, and is used to detect the air tightness of the bellows under pressurized conditions in real time.

5. The bellows fatigue testing device according to claim 4, characterized in that, A length detection unit is provided along the bottom of the corrugated pipe on the side away from the test frame axial direction. This unit works in conjunction with the dynamic moving unit to drive the test frame and the corrugated pipe to reciprocate and extend for sampling, thereby detecting the axial deformation dimension of the corrugated pipe.

6. The bellows fatigue testing device according to claim 5, characterized in that, The length detection unit includes a mounting block and a laser displacement sensor. The mounting block is fixedly installed at the end of the slide rail A away from the dynamic moving unit, and the laser displacement sensor is fixedly installed on the side of the mounting block close to the dynamic moving unit to detect the axial expansion and contraction of the corrugated pipe driven by the test frame.

7. The bellows fatigue testing device according to claim 1, characterized in that, One side of the dynamic moving unit is connected to the bottom of the test frame, and the dynamic moving unit drives the test frame to reciprocate to perform installation inspection and fatigue test on the corrugated pipe.

8. The bellows fatigue testing device according to claim 7, characterized in that, The dynamic movement unit receives real-time electrical signals from the position detection unit and the air pressure detection unit through the control unit, and adjusts its own movement distance and speed in real time based on the signal values.

9. The bellows fatigue testing device according to claim 8, characterized in that, The control unit outputs a counting detection command to the length detection unit for the working period corresponding to the bellows test, so that the length detection unit can switch to the counting detection working state.

10. A method for testing the fatigue strength of a bellows, characterized in that, The test method uses the bellows fatigue testing device according to any one of claims 1-9, and the test method includes the following steps: S1. Preparation steps: Place the bellows to be tested inside the testing mechanism, connect the electrical connection between the testing mechanism and the control unit, and pre-set the reference parameters of the position detection unit, air pressure detection unit and length detection unit through the control unit; S2. Limit detection step: Then, based on the preset parameters of the position detection unit, adjust the relative position of the bellows and the test mechanism to ensure that the center distance between the two matches the preset alignment standard. If the limit detection fails to meet the standard, the control unit shall prohibit the inflation of air into the bellows. S3. Air pressure test procedure: After alignment, the control unit injects gas into the bellows. After the air pressure reaches the preset parameter, the inflation stops and a pressure holding test is performed. If the air pressure value does not fall below the reference parameter during the pressure holding process, the air tightness is deemed to be qualified. If the air tightness test fails, the control unit prohibits the start of the length test. S4. Length detection step: At this time, the control unit issues a drive command to control the dynamic moving unit to drive the bellows to complete the reciprocating extension and retraction sampling, and cooperates with the length detection unit to verify the axial deformation dimension of the bellows. When the axial deformation dimension does not meet the standard, the control unit locks the dynamic moving unit and prohibits the start of the formal fatigue extrusion tensile test. S5. Inspection and qualification steps: After the limit, air pressure and length tests are all up to standard, the control unit finally controls the dynamic moving unit to drive the bellows to perform fatigue test. S6. Bellows fatigue test motion steps: During the reciprocating motion of the bellows driven by the dynamic moving unit, the control unit continuously collects the feedback signals from the air pressure detection unit and the position detection unit in real time. S7. Bellows fatigue test motion acceleration steps: If the air pressure and limit reference values ​​do not change after a preset number of cycles, the dynamic moving unit will gradually accelerate according to the preset gradient. During acceleration, the bellows will move left and right to complete the fatigue test. S8. Bellows fatigue test motion deceleration steps: When the air pressure and limit reference parameters deviate, the control unit will control the whole machine to stop working, and at the same time the dynamic moving unit will stop driving the bellows to run.

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